public class demo1 {

    public static void main(String[] args) {
        OverStudent s = new OverStudent();
        s.drink();
        s.lunch();
    }

}


class Person{
    public void lunch() {
        System.out.println("chifan");

    }

}
class Student extends Person{
    public void drink(){
        System.out.println("hereshui");
    }
}
class OverStudent extends Person{
    public void drink(){
        System.out.println("heliangshui");
    }
}
